1. Field of the Invention
The invention relates in general to a servo actuator-pivot assembly in a magnetic recording disk drive; and, more particularly to an actuator-pivot assembly which has corrugated end rings.
2. Description of the Background Art
Disk drives using magnetic recording of digital information store most of the information in contemporary computer systems. A disk drive has at least one rotating disk with discrete concentric tracks of data. Each disk drive also has at least one recording head typically having a separate write element and read element for writing and reading the data on the tracks. The recording head is constructed on a slider and the slider is attached to a suspension. The combination of the recording head, slider, and suspension is called a head gimbal assembly. In addition, there is an actuator, part of a servo system, which positions the recording head over the specific track of interest. The actuator first rotates the head gimbal assembly to seek the track of interest, and after positioning the recording head over the track, maintains the recording head in close registration to that track. The disk in a disk drive has a substrate and a magnetic layer on the substrate for magnetic recording. The slider carrying the recording head has a disk facing surface upon which an air bearing is constructed. The air bearing allows the slider to float on a cushion of air and to be positioned close to the disk surface. Alternatively, the slider surface facing the disk can be adapted for partial or continuous contact with the disk.
Each new generation of disk drive products generally has an increased density of recorded information. Over the past decade, most of the increase in density has resulted from making the width of the recorded tracks more narrow. As the width of recorded tracks become more and more narrow, greater burdens are placed on the mechanical performance of the actuator system to accurately position the recording head over the track of interest. Excess mechanical vibration, relatively large assembly tolerances, and mechanical distortions or deformations all contribute to a degradation of actuator and servo performance. The necessity of removing such effects is especially important as trackwidths approach a few tens of nanometers.
One source of mechanical deformation is the deleterious mechanical biasing which occurs when a pull screw is used to affix a pivot cartridge in the bore of an actuator arm. The use of a pull screw in an actuator assembly leads to very asymmetrical and uneven forces placed on the pivot cartridge. These uneven forces can make the assembly susceptible to vibrations and can degrade the performance of the actuator.
Thus, an improved method of attaching the pivot cartridge is needed which results in a much more uniform distribution of forces.